Hi eartha and welcome!

Our two German shepherds swim daily. I keep the chlorine level between 3 - 5 ppm and have never shocked the pool just because the dogs swim in it. They ingest a lot of water when diving and retrieving and the FC hasn't hurt them. I don't know anything about cats, can't help you there.

What have you been using to sanitize the pool? If you've put in such products as trichlor or dichlor tabs/ sticks/ pellets/ flakes you've really been using chlorine all along.